Synthesis, catalytic SiSi dehydrocoupling, and thermolysis of polyvinylsilanes [CH2CH(SiH2X)]n (XH, Ph)

Clear honey-like oil [CH2CH(SiH3)]n (PVS) with 40% ceramic yield was crosslinked by SiSi dehydrocoupling with the catalysts developed recently in our laboratory such as Group 4 metallocene Cp2MCl2/Hydride (M=Ti, Zr, Hf; Hydride=Red-Al, N-Selectride, Super-Hydride) combination, group 6 metal hexacarbonyl M(CO)6 (M=Cr, Mo, W), and group 8 metallocene Cp2M (M=Co, Ni) to give insoluble network of polyethylene–polysilane hybrids. Their themolysis in argon significantly improved ceramic yields of 62–80%. The thermogravimetric analysis ceramic yields of the crosslinked PVS with the Group 4 metallocene were higher than those with the Group 6 and 8 metal complexes. The most effective dehydrocoupling catalyst was Cp2MCl2/N-Selectride combination. Similarly, white sticky solid [CH2CH(SiH2Ph)]n (PPVS) with 35% ceramic yield was modified by SiSi dehydrocoupling with the Group 4 metallocene Cp2MCl2/Red-Al (M=Ti, Zr) combination catalysts. Thermolysis of the crosslinked PPVS under argon to 800 °C showed improved ceramic yields (47–50%), which were lower than those of crosslinked PVSs due to low degree of crosslinking and high C/Si ratio (C/Si=8).